able one-Jami; that myv patent-r cIaims should; not: be: limited. toe the: specific; sthucturer-hereinolescribed: Also,- Whil'ei I have described? generally severaliimportant features of my inventiong there are other important featuresv that will be described particularly in' the specification and will be o1aimedin'the claims appended hereto;

in any other place where a cylinder lock core may be inserted for operating lock mechanism.

Referring now to the drawings, Fig. 1 is an elevation of a padlock in which my invention may be embodied. Fig. 2 is a section of the padlock of Fig. l but with the removable lock core removed therefrom. Fig. 3 is an elevation of the removable lock core as it would. appear when removed from the padlock housing. Figs. 4 and 5 are sections taken alon lines 44 of Fig. 2 showing.

the shackle of the padlock in locked position and in unlocked position. Fig. 6-is a composite section taken along lines 6--6 of Figs. 2 and 3, so as to show the removable lock core within the padlock. Fig. 7 is a view taken along the same lines as Fig. 6 but with the change and retainer plu s rotated to release the removablelock core for movement out of the padlock housing.

Fig. 8 is a plan view of an assembl plate used in my invention. -Fig. 9 is a plan View of the rotary bolt used in my padlock and illustrating the relation of a lug of the rollback cam relatively thereto. Fig. 10 is an exploded view of the change plug and the plug retainer detent. Fig. 11 is an exploded'view of the rollback cam and the bolt with the bolt spring positioned therebetween. Fig. 12 is a section'taken along the lines l2|2 of Fig. 3. Figs. 13 and 14 are front end views of the removable lock core looking upwardly at the bottom of Fig. 3 and showing the two key plugs in' the positions of Figs. 6 and 7 respectively. A Referring now more particularly to the drawings. and especially Figs. 1-5 inclusive, my invention is adapted for use Within a padlock housing I (l with which cooperates a shackle ll of the usual type well known in the art. This shackle has a relatively short'leg mounted in a bore I2 in the" housing H3, and a relatively long leg housed in a bore l3'of the padlock housing 10. A spring [4 tends to move the shackle H toward release position butthe shackle is restrained against such movement by locking balls I5, [6 and [1. Thus, locking ball l5 is adapted to cooperate with a groove 13 in the long shackle leg while ball I 1 cooperates with a groove IS in the short shackle leg.

' For controlling the locking balls I5, l6 and I1, I utilize a rotary bolt having release depressions 2| and 22, which when placed opposite the balls l5, l6 and I! as shown in Fig. 5, allow release movement of the said balls and out of locking grooves l8 and IS.

A spring 23, best shown in Fig. 11, has an upper end 24 that is adapted to enter a bore 25 in the padlock casing 10 as best illustrated in Fig. 2. The lower end 26 of the spring 23 enters a radial slot 2 'l of the bolt 23, the springbeing so formed that when so positioned, it normally urges the boltlfi into its locking position of Fig. 4. Directly underneath the flange 28 of the bolt 20 there is mounted a rollback cam 29 as best illustrated in Fig. 2, the cam itself being best shown in Fig. 11. This cam has an integral lug 30 that operates in a slot 31 of the bolt 20 for rotating the bolt from the locking position of Fig. 4 to the release position of Fig. 5. For holding the bolt 20 and the rollback cam 29 in the position of Fig. 2,v

I utilize an assembly plate 33 best illustrated in Fig. 8. This assembly plate is formed with a pair of slots 34 whereby it may he slipped over pins 35" extending from rollback cam 29, and against the surface 36 of the padlock housing 10.. The assembly plate 33 may then be staked into position to maintain the parts assembled as shown in Fig. 2.

4 Those skilled in the art will fully understand that the rollback cam 29 is rotatable by a suitable key plug through the medium of its pins 35. the slots 34 of the retainer plate 33 being formed to allow such rotation. Through the lug 38, the bolt 20 will be rotated by rollback 29 to allow movementof the locking balls l5 and IB into depressionsi I, 22 as shown in Fig. 5. In that position of the partsQthe shackle II will spring upwardly under the influence of its spring [4 so as to hold the bolt 20 in its release position. The rollback. cam 29 may now be operated back to its normal position because of the relation of the lug 33 to slot 3l of the flange 2B of bolt 20. The

vpurpose of this structure is to allow the removal ofthe key from the key plug that is used for rotating the rollback cam 29. Thereafter, the downward movement of the shackle II will align its locking grooves I8 and IS with the balls 15 and 11. When this is done, the said balls will move into locking relation tothe shackle while the bolt 2!] is rotated by sprin 23 into its position of Fig. 4 to maintain the balls 15 and H in locking position. At this point it will be well to indicate that the rotation of the bolt 20 is best limited by a stud 37 'that is. inserted into position through the outer wall of the housing 10. P

The housing in of the padlock is formed with describe the detailed structure of the removable lock core of my'inverition.

Reference numeral indicates generally my removable'lock core, over the front end of which is fitted a scalp 4! that may be secured thereto by scre ws'or staking, all as those skilled in the art'will appreciate. A change key plug 42, hav

ing a keyway 43, is mounted'within removable lock core 40 for rotation therein. For controlling the rotation of the change key plug 42 I retainer key plug is formed with. a keyway 48 V and'is controlled in its rotation relatively to the removable lock core 40 by tumblermchani'sm designated by reference letter P. mechanism P comprises standard pin tumbler mechanism known in the art and embodying here ,a series of'springs l'la, drivers 48 and tumblers 49 mounted in aligned bores that are formed in the plug-41 and the removable lock core 40} Those skilled in the art will readily appreciate that when a change key C is inserted in the keyway 43 as best illustrated in Fig. 12 for setting the tumbler mechanism P, change key plug 42 may be rotated from its position of Fig. 12 to its position of Fig. 14. Similarly, when a retainer key R. is inserted into plug 41 to set' the tumbler mechanism P, the retainer; plug 41 may be rotated from the position of The tumbler area-ore the retainer 5!! lies within theretainerslbt 39 of'the'padiock housing Hland preventsendwfse movement. of lock core 40- out of the said housing; Asshown'inFig. 'r, the'retai'nerbll is completelyout of-the. retainer slot 39, and the re"- movable lock core maybe moved out of the opening 38" of padlock housing H]. For limiting the throw of the retainer 51! and the retainer plug 41, a. limit lug 52'; is: secured to the upper" end of the removable lock. core 40" asfbest'ill'us trat'ed'in Figs. 3 and'7.

and each" of said key plugs having a keyway therein whereby said tumblers" are key set" andsaid k-ey plugs are released for movement relax-- tiv'ely to saidlook core; andretaining means? movable between a release position and a: lB-f taming; position for retaining said lock core said. housing and adapted for movement by one of' said key plu'gs out ofretaining p'ositik'ln and" into a release position.

22 In a lock of. the? class described; a housing;-

a. look oore removablymounted in said housing;

a pair of independently movable key" plugsj movably mounted in said'lock core andea'ch" havingakeyway, an independent set. of. tumblers extending between each of said plugs and sai'di'.

lock. core and. adapted for positioning. by keys" in the keyways of said'key plugs to releasesaidkey plugs for movement relatively to saidlocit;

- for movementby'one' of saidl'key plugs out"'of"re= taining, position and intoa release position.

out otretaining. position. andinto a. release .p'osiy each having a keyway, said lock core having a ascents series, of tumbler j bores formed in alignment with boresin one of said key plugs when said key plug is in an initial locked position, said lock core having a second series Of tumbler bores formed in alignment with bores in the other of said key plugs when said other key plug is in an initial locked position, tumblers mounted in said bores for positioning by keys inserted into the keyways of said key plugs, and a cam secured on one of said key-plugs adapted for rotation therewith into a slot in said housing.

6. ,In a lock of the class described, a housing, a lock core removably mounted in an opening formed in said, housing, a pair of key plugs rotatable in said lock core on parallel axes and each having a keyway, said lock core having a series of tumbler bores formed in alignment with bores in one of said key plugs when said key plug is in an initial locked position, said lock core having a second series of tumbler bores formed in alignment with bores in the other of said key plugs when said other key plug is in an initial locked position, tumblers mounted in said bores for positioning by keys inserted into the keyways of said key plugs, a retainer for locking said lock plug is in an initial locked position, said lock core having a second series of tumbler bores formed in alignment with bores in the other of said key plugs when said other ke plug is in an initial'locked position, a retainer for locking said lock core in said housing, means whereby said retainer is movable by one of said key plugs to release said lock core for movement out of said housing, locking mechanism in said housing, and means whereby said locking mechanism is movable by the other of said key plugs.

8. In a lock of the class described, a housing,

a lock core removably mounted in said housing, a pair of independently movable key plugs movably mounted in said lock core and each having a keyway therein whereby said key plugs are released by key operation 'of tumblers for move ment relatively to said lock core, meansretaining said lock core in said housing adapted for movement by one of said key plugs out of retaining position, and means whereby movement of the other of said key plugs is a requisite to the move-.

ment of said retainer out of retaining position.

9,-In a lock of the class described, a housing, a lock core removably mounted insaid housing, a pair of independently movable key plugs mova-bly mounted in said lock core and each havin a keyway, an independent set of tumblers extending between each of said plugs and said lock core and adapted for positioning by keys in the keyways of said key plugs to release said key plugs for movement relatively to said lock core,

means retaining said lock core in said housing adapted for movement by one of said key plugs out of retaining position, and means whereby movement of the other of said key plugs is a requisite to the movement of said retainer out of retaining position.

' 10. In a lock of the class described, a housing,

a lock core removably mounted in said housing;

a pair of independently movable key plugs movably mounted in said lock core and each having a keyway therein whereby said key plugs are releasedby key operation for movement relatively to said lock core, a cam rotatable by one of said key plugs and adapted when in one position to coact with said housing to retain said core within said housing, and means whereby movement of theother of said key plugs is a requisite to the movement of said cam out of retaining position,

relatively to said housing. a

11, In alock of the class described, a housing,

a lock core removably mounted in said housing, a pair of independently movable key plugs movably mounted in said lock core and each having a key way, an independent set of tumblers extending between each of said plugs and said lock core and adapted for positioning by keys in the keyways of said key plugs to release said key plugs for movement relatively to said look core, means retaining said lock core in said housing adapted for movement by one of said key plugs out of retaining position, means whereby movement of the other of said key plugs is a requisite to the movement of said retainer out of retaining position, and means in said housing movable by movement of the other of said key plugs.

12. In a lock of the class described, a housing, a lock core removably mounted in an opening formed in said housing, a pair of ke plugs rotatable in said lock core and each having a keyway, tumblers adapted for positioning by keys, inserted into the keyways of said key plugs to release said key plug for rotation, means whereby the rotation of one of said key plugs is a prerequisite to the rotation of the other of said key plugs, retaining means for retaining said lock core in said housing, and means whereby said other key plug moves said retaining means from a retaining to a release position.

13. In a lock of the class described, a housing, a lock core removably mounted in an opening formed in said housing, a pair of key plugs movable in said lock core and each having a keyway, tumblers adapted for positioning by keys inserted into-the keyways of said key plugs to release said key plugs for movement, a retainer for locking said lock core in said housing, means whereby said retainer is movable by one of said key plugs to release said lock core for movement out of said housing, and means whereby the movement of the other of said key plugs is a-requisite to the movement of said retainer out of retaining position.

14. In a lock of the class described, a housing, a lock core removably mounted in an opening formed in said housing, a pair of key plugs rotaj able in said lock core in parallel axes and each having a keyway, said lock core having a series of tumbler bores formed in alignment with bores in .oneoi said key plugs when said key plug is in an initial lockedposition, said lock core having a second series of tumbler bores formed in align- -ment with bores in the other of said key plugs when said other key plug is in an initial locked position, a retainer for locking said lockcore in said housing, means whereby said retainer is movable by one of said k-ey plugs to release said lock core for movement out of said'housing, looking mechanism in said housing, means whereby said locking mechanism is movable by the other of said key plugs, and means whereby the rotation of the other of said key plugs is a requisite 15. In a lock of the class described, a housing,

a lock core mounted in an opening in said housing, a cam rotatable on said housing, a key operated plug rotatable in said lock core, means of connection brought into engagement between said key plug and said cam when said lock core is inserted into said housing, a second key operated plug rotatable in said lock core, a retainer for said lock core movable through rotation of said second key plug toward a release position, a part rotatable with said first key plug and cooperable with said means of connection, said part preventing the movement of said retainer to a release position by said second plug until said part taining said key plug in said lock core, and por- 25 tions of said pins maintaining said detent against movement out of retaining position.

17. In a lock of the class described, a housing,

, 10 a lock core mounted in an opening in said housing, a cam rotatable on said housing, a key operated plug rotatable in said lock core, pins extending from said core and adapted to enter bores in said key plug when said lock core is inserted into said housing opening, a retainer detent for retaming said key plug in said lock core, portions of said pins maintaining said detent against movement out of retaining position, a second key operated plug rotatable in said lock core, a retainer for said lock core rotatable by said second key plug out of retaining position, and a part of said retainer detent of said first plug preventing rotation of said second plug and retainer until said first plug is rotated.

JOHN P. ANDREW.

REFERENCES CITED The following references are of record in the file of this patent: